In recent years, as a seat core member for a vehicle such as an automobile (hereinafter also referred to as seat core member), a seat core member formed in such a manner that a frame member made of metal or the like is disposed in a thermoplastic resin expanded beads molded body (hereinafter also referred to as expanded beads molded body) has been used. The frame member may be provided with a latch part for fixedly attaching a seat to a vehicle body.
Patent Literature 1 discloses an example of such a member that includes the expanded beads molded body, the frame member, and the like (seat core member). In Patent Literature 1, there is proposed a member in which a frame member for reinforcing a cushion material is attached to an expanded beads molded body, and a member in which a frame member is attached to an expanded beads molded body with a part of the frame member embedded in the expanded beads molded body (hereinafter also referred to as conventional art 1).